Quick-make-and-break safety switch



June 17, 1930. A. E. GRISWOLD QUICK MAKE AND BREAK SAFETY SWITCH Filed Dec. 27, 1926 2 Sheets-Sheet l l l n l l l' n n n f l i f n a u 5 i 5 5 l l n 5 i i lNVENTOR June 17, 1930. A. E. GRlswoLD 1,764,401

QUICK MAKE AND BREAK SAFETY SWITCH Filed D626 27, 1926 2 Shets-Sheet 2 Patented June 17, 1930 ANDREW E. GRISWOLD, OF SEATTLE, WASHllINGr'lOlll QUICK-MAKE-AND-BREAK SAFETY SWITCH i Application led December 27, 1926. Serial No. 157,154.

This invention relates to improvements in electric switches, and more particularly to safety switches of the double break character used in circuits carrying heavy loads; the

principal object of the invention being to provide such switches with a quick make and quick break mechanism that is very positive in its action.

More specifically stated, the object of this invention resides in the provision of a switch mechanism wherein springs under tension are used as a means for throwing the switch blade carriage from one position to another to bring the blades into and from the switch jaws, and which act under the control of a hand lever to move the switch blades so as to make a very quick brealor quick closing of the circuit. -c

Other objects of the invention reside in the various details of construction and combination of parts of the switch mechanism, particularly in the blade carriage and travel bar construction. y

vIn accomplishing these and other objects of the invention, I have provided the improved details of construction the preferred forms of which are illustrated in the accompanying drawings, wherein- Figure 1 is a side elevation of a switch mechanism embodied by the present invention, a part of the switch housing being broken away for better illustration.,

Figure 2 is a central, vertical section of the same. M y

Figure 3 is a front view of the switch mech anism, the front of the housing, and rthe coni trol lever being removed for better illustra- Figure 4 is a horizontal section taken on the line 4-4 in Figure 3. 1 v

Figure 5 is a sectiona detail showing the portion of the switch blades when in closed position and illustrating, in dotted lines, the movement of the actuating means permitte by the lost motion connection between the switch carriage and travel bar.

Referring more in detail to the drawings- In its preferred form of construction, the switch is contained within a sheet metal housing designated at 1, having a door,` 2 closing its upper front portion that is hingedly mounted, as at 3, so as to swing outwardly and downwardly'to open position. The lower front portion of the housing is closed by a Iixed panel 4 that is provided with a slot 5 55 through which is slidably extended a link 6 -whereby connection is made between the switch mechanism within the housing and anactuating lever 7 that is pivotally mounted, as at 8, on a bracket 9 fixed to the outside 60 of the panel 4. The control lever 7, in this instance, extends downwardly from the pivot point and at its upper end is provided with an extension l() adapted to engage with a lug 11 on the door 2, so as to prevent the door being opened except at times when the lever is in the position it assumes when the switch is pen.

Fixed to the back wall within the housing,

is an insulating panel 14 which may be of 70 slate, ebony, or any other suitable material and, mounted on this, are paired, vertically alined switch jaws 15-15, 16-16 and 17-7172 as shown in Figure 3, each jaw being connected with a terminal 18 of a circuit.f75 Fixed in the panel midway of the upper and lower jaws of the switch and extending forwardly therefrom, in the same horizontal plane, are two parallel guide posts 19-19 on which the switch blade carriage is slidably mounted. This carriage comprises two bars of insulating material, designated at 20 and 20', between which three vertically disposed switch blades 21, 22 and 23 are rigidly clamped; the bars 20-20 being notched, as 85 shown at 24 in Figure 4, to receive the edges of the blades in such manner as to prevent their slipping from proper position. Extending through the bars 20e-20 are tubular thimbles 25-25, which are clinched over 90 at their ends to draw the bars tightly against the blades and to hold all the parts rigidly and rmly together. Through these thimbles d the posts 19-19 slidably extend and the car-y riage maybe moved inwardly or outwardly along these posts to bring the blades into or from the switch jaws.

Also, fixed in the bars 20-20, in parallel relation to the thimbles 25-25 are thimbles 26-26 withinwhich bolts 27-27 `are con- 100 tained. These bolts are slightly longer than I their inner ends, against the heads 30 and,

at their outer ends, against the p-late 32 that overlies theouter ends of the thimbles and that yieldably urges the carriage toward the travel bar 29; the plate 32 being provided with apertures through which the bolts slidably extend. y

The travel bar 29 has a plate 35 fixed to its outer face, centrally between the posts, and to this is operatively connected the inner end of the link 6 through which the carriage, by movement of the control lever 7, is actuated inwardly or outwardly for the purpose of closing or opening the circuit.

Fixed within the housing l, in parallel relation to the side walls and spaced there- "from, are plates 40 and 40 which have cutout portions providing guide slots 41-41 through which thev ends of the travel bar 29 extend and which permit movement of the bar toward or from the back of the housing. Extending transversely between the plates, above and below the upper and lower rows of switch jaws as shown in Figures 2 and 3, are rods 42-42. These are revolubly mounted and their ends extend slightly be-r'y yond the plates and have levers 43-43 iixed thereon.

The paired levers located at the same side of the housin are pivot-ally connected at their inner en s by means of short links 45 Vwith the adj acent end of travel bar 29 and their outer ends are vconnected by a coiled spring 46 which is under considerable tension. When theswitch is open the outer ends of the paired levers extend rearwardlyat the same angle with respect to the line of their pivot points and they terminate adjacent the rear wall of the housing, and the spring yieldably holds the switch in open position. When the switch is closed, the closing action causes the outer ends of the levers to swing upwardly and when they pass over the dead center line of the pivot points, the spring then acts to throw the inner ends of the levers and the switch bar inwardly. The levers on' each cross rod are fixed rigidly thereto, so that allof the levers operate together to cross the dead center points at Ythe same time.

tion, as shown 1n Figure 5,

as to the dotted line is actuated inwardly, position in Figure 2, andthis, through the connecting link 6, moves-the travel bar 29 l inwardly and, since the bar is seated against the switch blade carriage, the latter will be actuated inwardly along the guide posts. Inward movement of the travel bar 29 causes the levers 43--43 to swing forwardly and as their outer ends pass over the dead center line of the pivot points, the springs 46 cause the switch to be thrown quickly to snap thc blades into the jaws.

When the switch is to be opened, the lever 7 is pulled outwardly. This causes the travel bar 29 also to be moved outwardly and the levers 43-43 to be swung rearwardly. During the initial outward movement of the travel bar there will be no movement of the switchv carriage due to the fact that the grip of the jaws against the blades is made suiiicient to overcome the pressure ofthe springs 31; however, when the heads 30 of the bolts 27-27 engage with the ends of the thimbles through which the bolts extend, the carriage will be moved outwardly. Due to this lost motion connection, the outward movement ofthe carriage does not start until the levers 43-43 are about to pass over the dead center line of their mounting points, then as they snap` over, the switch is thrown open quickly. Without this lost motion connection, the switch blades would be unseated slowly from the jaws before the springs could function to throw the switch and there would be an undesirable arcingdue to this slow movement. l

Having thus described my invention, what I claim as new therein an desire to secure by Letters-Patent, is:

1. A switch of the character described, comprising a mounting base, switch jaws on the base, guide posts fixed to the base, a carriage slidable on the guide posts, blades mounted by the carriage and movable ltherewith into and from the jaws, a pivotally mounted control lever '.having a lost motion connection with the carriage and through which the carriage may be actuated toward or from the jaws, and mechanism under spring tension for yieldably retaining the switch in on or off positions, and for throwing the carriage quickly between on and off positions after it predetermined movement by the control ever.

2. A switch ofthe character described, comprismg a mounting base, switch jaws on the mounting base, guide posts fixed to the base, a carriage slidable on the posts, blades mounted by the carriage and movable therewith into and from the jaws, avtravel bar l aving a lost motion connection with the carriage, a pivotally mounted control lever, a link connecting the lever with the travel bar, paired levers pivotally mounted between their ends and having ends operatively connected with the travel bar, lsprings connecting the other ends of the paired levers and operable to yieldably retain the carriage at on or ofi positions and to throw the carriage quickly fromone position to the other'incidental to a movement of the travel bar by the control lever that will carry' the spring connected '5 ends of said levers from one side to the other of the line of their mounting points.

3. A switch of the character described, comprising a mounting base, switch jaws on the base, guide posts xed on the base, .a carriage slidable on the guide posts from and toward the jaws, switch blades mounted by the carriage and movable therewith tinto, and from f the jaws, a travel bar slidable on the posts,

bolts fixed to the travelbar and extending slidably through openings in the carriage and providing a lost motion connection between the carriage and bar, 4a pivotally mounted control lever, a link connecting the control lever with the travel bar., whereby it may be 2o actuated to move the carriage, paired levers pivotall mounted between their ends at opposite s'ldes of the carriage, links-connecting the inner ends `of the levers with the ends of the travel bar, springs under tension connect'- ing the youter ends of the paired levers and operable to throw the levers to move`the switch carriage quickly between on and o positions when the spring connected ends of said levers are moved bytheir connection with the travel bar from one side to the other of the dead center line ofthe pivot points of the levers.

4. A switch of the character described, comprising a mounting base, switch jaws on the 35 base, guide posts ixed to the base, a carriage slidable on the posts, blades mounted by the carriage and movable therewith into and from the jaws, a travel bar adapted to en- 40 to on'position, bolts fixed'to the travel connection with-the lever, cross shafts extended revolubly through the housing, levers fixed to the ends of said shafts, links connecting the inner ends of the levers with the ends of the travelbar, springs under tension connecting the outer ends of the paired leversl and operable to throw the levers ito move the day of November, 1926.

' ANDREW E. GRISWOLD.

gae with the carriage and to move it from C bar and extending slidably through the carriage, nuts on the ends of the bolts whereb the carriage ma be movedfrom on to will position, yielda lemeans for urging lthe carriag'e toward the travel bar, mechanism under sprin tension for'throwing the travel bar quick y between du and oli positions, a

control lever and means connecting the con'- trol lever with the travel bar.'

5. A switch of the character described comprising a housing, a mounting base within the housing, switch jaws on the base, guide posts fixed on the base, a carriage slidable'on the posts toward and from the jaws, switch blades mounted in the carriage and movable therewith into and from the jaws, a travel bar, bolts having ends fixed in the travel bar and with theirother ends slidabl. mounted inthe carriage and having nuts t ereon for limiting their travel, springs about the bolts and bearings against the nuts and carriage to urge the latter toward the travel bar, a pivotally mounted control lever, a link connected at one end with the travel bar and e5 connected at its other. end by a pin and slot 

